Acibenzolar-s-methyl in rust and blotch control in field conditions

The objective of this study was to evaluate the effect of acibenzolar-S-methyl (ASM) resistance inductor, associated or not with the fungicide azoxystrobin + cyproconazole base, the control of Cercospora leaf rust and coffee under field conditions. The study was conducted during two harvest years (2007/2008 and 2008/2009), in commercial planting of the Mundo Novo cultivar. Used treatments were: ASM (25 g ha-1) applied omnthly five times (from December to April of each harvest year); fungicide (500 mL ha-1) and the mixture fungicide (500 mL ha-1) + ASM applied three times (December, February and April of each harvest year); the mixture fungicide (500 mL ha-1) applied three times (December, February and April of each harvest year) + ASM applied five times (December to April of each harvest year); the mixture fungicide (750 mL ha-1) applied two times (December and March of each harvest year) + ASM applied five times (December to April of each harvest year) and witness. Rust control (84%) given by ASM was statistically equal to the treatment with fungicide (94%) in the low harvest year (2008/2009), when diseases intensity was not as high as in the high harvest year (2007/2008). In the high harvest year, ASM did not control blotch, while in the low harvest year this product controlled blotch (77%) at an inferior rate compared to fungicide (92%) and mixtures (89 to 94%). In low harvest years, ASM can be used in rust and blotch control for coffee trees and showed compatibility with the fungicide ciproconazole + azoxystrobin.